I waste too much of my brain engaged in trivial thoughts. I’m frequently tempted to call the toll-free numbers on the sides of food packages, just to see if anyone is really there. I struggle to remember what ever happened to those poor people stranded on Gilligan’s Island. Mostly, I wonder how extension cords manage to tie themselves up in knots.
Every so often, though, I experience a fleeting moment of perspective. This tends to occur when I’ve turned my attention to the night sky, that dark expanse filled with planets, stars, galaxies, and too many inscrutable mysteries to count.
How big is the universe? How did it begin? Will it go on forever, or will it end someday – and if so, how? And is there anyone else out there, or are we alone?
These are the questions science and religion have been trying to answer for thousands of years. If we knew where we came from, maybe we could figure out why we’re here and where we’re going.
The astronomy books tell us that right before the Big Bang, everything in the entire universe was packed into a point much smaller than the period at the end of this sentence. What the books fail to mention is that it must have been smaller than the period at the end of almost any sentence. It’s just one more quirk of nature that all periods are roughly the same size.
I may dwell on the diameter of punctuation marks for a while, but I can stall for only so long, and then I’m forced to return to the bigger issue, which is the universe and its infinite compression. It doesn’t seem possible, does it? The universe being that small, I mean. If you told me South Dakota was once the size of an English muffin, I’d have a hard time believing it, or that Baltimore could have fit inside a plastic sandwich bag. I can barely imagine a toaster oven ever being that tiny. Yet, the theory states that everything that has ever existed was once crammed into something called a singularity, a dot too minute to measure. I think about this idea whenever I try to hang another coat in the closet, or squeeze a container of leftover mashed potatoes into the refrigerator, or close my underwear drawer. You can get just so much stuff into a given space, and that’s it.
How is it that such limits don’t apply on the largest of scales? The universe has a lot of really big things in it. Heavy things. There are black holes, for example, that are forty billion times as massive as the sun. The Milky Way has a hundred billion stars, many with huge planets orbiting them. There are more than a hundred billion galaxies that we can see, and a lot more dark matter that we can’t. I accept the fact that atoms are mostly empty space, but that doesn’t seem like enough of an explanation. I’ve seen cars that were flattened to the size of a coffee table, but that’s as little as they would get.
I wish I could find an astrophysicist who would sit down and explain this to me, and who wouldn’t be allowed to leave until I understood it. On the other hand, I also wouldn’t mind if he admitted that he doesn’t get it either. That might be even more satisfying.
After the Big Bang, the universe expanded quickly. So quickly that scientists try to describe what was happening after a millionth of a second, and then a millionth of a second after that. I don’t really know how anyone can talk that fast, but then, I’m not a scientist.
The universe in its present state is gigantic in a way that is impossible to fathom. And it’s getting bigger. Our galaxy is a hundred thousand light-years across. That means that a beam of light, traveling at 186,000 miles per second, would take a thousand centuries to get from one end to the other. The nearest star to our sun is twenty-five trillion miles away.
Here’s a photograph taken by the Hubble Space Telescope:
It shows a slice of the sky – a slice whose width is one-third the diameter of the full moon. That thin region contains more than seven thousand galaxies, many just like our own. If we could step back far enough, we would see clusters of galaxies, and clusters of clusters.
With that many stars and solar systems, some people believe the universe must be teeming with life. I think so, too, although I don’t care for the word teeming. It reminds me of a swamp filled with dragonflies and bullfrogs. I know astronomers would be thrilled to find dragonflies and bullfrogs on another planet, but I’m hoping for something with a little more aptitude for abstract conversation.
Here’s another Hubble picture, this one of the Horsehead Nebula:
Made mostly of hydrogen and dust, this object is about five light years tall – in other words, its height is greater than the distance from our sun to the nearest star. And it’s just a part of a much larger cloud. The Horsehead Nebula is fifteen hundred light years away, which means the photons that formed this image began their journey to Earth when Justinian the Great became Byzantine Emperor in 527 AD. I don’t know what was so great about Justinian, but I bet he never heard of the Horsehead Nebula. I also don’t understand why the universe needed to be so incomprehensibly enormous. It actually makes me angry sometimes, especially when I can’t find a place to park.
Some mathematical models of the universe suggest there was a time when even empty space didn’t exist. Different theories say there’s no such thing as empty space. Others claim the universe is finite and has an edge, or that it’s infinite, and that if you could travel long enough in a straight line, you’d end up back where you started. Which is exactly what I seem to have done. I’m still curious: Has anyone ever called the toll-free number on the back of the Twizzlers package? And what did ever become of those seven stranded castaways? I spent the best years of my childhood caught up in their fate, and then missed the outcome. I was probably too busy staring at the night sky. Or, more likely, trying to untangle an extension cord.